MAIZE PROTEINS INDUCED BY DNA DAMAGING AGENTS ULTRAVIOLET-B AND MUTATOR ACTIVITY

该子项目是利用NIH/NCRR资助的中心赠款提供的资源的许多研究子项目之一。子项目和研究者（PI）可能从另一个NIH来源获得主要资金，因此可以在其他CRISP条目中表示。所列机构为中心，不一定是研究者所在机构。玉米像所有其他植物一样缺乏生殖系。在生命周期的后期，花中存在的少量营养干细胞分化为前萌发细胞;这些细胞经历减数分裂产生单倍体孢子，其通过有丝分裂形成生命周期的单倍体阶段。鉴于这种生命周期，营养细胞中发生的DNA损伤如果不修复，可能会传递给后代;蛋白质、RNA或脂质的其他形式的细胞损伤如果不修复，也可能损害植物的生长和繁殖。为了了解基因组的完整性是如何保持的，以及玉米如何应对持续的损害，使用了两种DNA诱变剂：UV-B辐射，阳光的天然成分，和MuDR/Mu DNA转座子。转录组分析和蛋白质组学正在被用来发现各种体细胞和生殖组织对这些药物的适应反应范围。使用二维分离（通过等电点和大小）来分离处理和对照组织的主要蛋白质，提供约3000种解析蛋白质类型的数据。将蛋白质分类为通过特定处理未改变、增加或减少，并且回收显示一致改变的蛋白质用于鉴定。所有的蛋白质鉴定都是与UCSF质谱设施合作进行的;到目前为止，已经通过质谱指纹和测序鉴定了大约150种蛋白质。在这些蛋白质中，有一些是从转录组谱预测的，还有一些以前没有参与对UV-B或转座子诱导的基因组损伤的反应的蛋白质。 转录组分析和蛋白质组学数据的结合用于确定涉及哪些信号转导途径和细胞过程;验证实验包括对所确定的关键过程中的突变体进行遗传分析，即通过证明突变体显示出增加的UV-B敏感性。目前的工作重点是阐明蛋白质的翻译后修饰，这些蛋白质没有被治疗大量改变，然后通过质谱法进行鉴定。这些研究可能会突出对治疗的最快速反应。

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. Maize like all other plants lacks a germ line. Late in the life cycle a small number of vegetative stem cells present in flowers differentiate as pre-germinal cells; these cells undergo meiosis to produce haploid spores, which divide by mitosis to form the haploid phase of the life cycle. Given this life cycle, DNA damage that occurs in the vegetative cells could be transmitted to the progeny if it is not repaired; other forms of cellular damage to proteins, RNA, or lipids could compromise plant growth and reproduction if not repaired as well. To understand how integrity of the genome is maintained and how maize responds to continuous damage, two DNA mutagens are employed: UV-B radiation, a natural component of sunlight, and MuDR/Mu DNA transposons. Transcriptome profiling and proteomics are being used to discover the range of acclimation responses to these agents in various somatic and reproductive tissues. Two-dimensional separation (by isoelectric point and by size) is used to fractionate the major proteins of treated and control tissues, providing data on ~3000 resolved protein types. The proteins are classified as unchanged, increased or decreased by specific treatments, and the proteins showing consistent alterations are recovered for identification. All of the protein identification is conducted in collaboration with the UCSF Mass Spectrometry Facility; to date, about 150 proteins have been identified by mass fingerprinting and sequencing. Among these proteins are a number predicted from the transcriptome profiling as well as proteins not previously implicated in responses to either UV-B or transposon-induced genomic damage. The combination of transcriptome profiling and proteomics data are used to determine which signal transduction pathways and cellular processes are involved; verification experiments include genetic analysis of mutants in key processes identified, i.e. by demonstrating that mutants show increased UV-B sensitivity. Current work focuses on elucidating post-translational modifications of proteins that were not altered in abundance by the treatments, followed by identification by mass spectrometry. These studies will likely highlight the most rapid responses to the treatments.